In an information system for performing a data processing by using data stored on a database, speeding up of the processing is realized through a parallel processing by a plurality of data processing systems. Each data processing system in this manner duplicates data on the database. Therefore, data can be accessed at a high speed, and concentration of accesses to the database can be avoided.
EPCglobal U.S., “The EPCglobal Network™,” [online], EPCglobal U.S., [Searched on December 16, Hei. 16 (2004)], Internet                <URL:http://www.epcglobalus.        
followed by: org/Network/Network.html>
provides, as an application example of the information example, EPC-IS (Electric Product Code-Information Services) which controls attribute data for each product by adding a wireless tag to the product or the like. Such an information system individually controls attribute data for each product, and hence it needs to control large amounts of data and requires a large-scale distributed system. In the EPC-IS, the attribute data for each product is controlled by a representation form called PML (Physical Markup Language) (Please refer to Christian Floerkemeier et al., “PML Core Specification 1.0,” [online], Sep. 15, 2003, EPCglobal Inc., [Searched on December 16, Hei. 16 (2004)],                <URL:http://www.epcglobalinc.        
followed by: org/standards_technology/Secure/
followed by: v1.0/PML_Core_Specification_v1.0.pdf>).
The EPC-IS based attribute data control has a feature that there are many inquiries to the attribute data and an update is rarely made. Therefore, each data processing system can duplicate the attribute data on the database and efficiently process them as far as no update occurs.
Yair Amir and Ciprian Tutu, “From total order to database replication,” in Proc. of ICDCS 2002, pp. 494-, 2002., Haifeng Yu and Amin Vahdat, “Minimal replication cost for availability,” in Proc. of PODC 2002, pp. 98-107, 2002., Chi Zhang and Zheng Zhang, “Trading replication consistency for performance and availability: an adaptive approach,” in Proc. of ICDCS 2003, pp. 687-695, 2003., and Khuzaima Daudjee and Kenneth Salem, “Lazy database replication with ordering guarantees,” in Proc. of ICDE 2004, pp. 424-435, 2004., disclose update processing methods for storing update operations onto a database by arranging them in order, and applying these update operations to duplicated data. Xueyan Tang and Samuel T. Chanson, “Minimal cost replication of dynamic web contents under flat update delivery,” in IEEE Trans. Parallel Distrib. Syst. 15(5): 431-439, 2004., Serge Abiteboul, Angela Bonifati, Gregory Cobena, Ioana Manolescu, and Tova Milo, “Dynamic xml documents with distribution and replication,” in Proc. of SIGMOD Conference 2003, pp. 527-538, 2003., and Ugur Cetinternel, Peter J. Keleher, and Yanif Ahmad, “Exploiting precision vs. efficiency tradeoffs in symmetric replication environments,” in Proc. of PODC 2002, p. 128, 2002., disclose, as other update processing methods, update processing methods for transmitting only update results to a database. Specifically, Xueyan Tang and Samuel T. Chanson, “Minimal cost replication of dynamic web contents under flat update delivery,” in IEEE Trans. Parallel Distrib. Syst. 15(5): 431-439, 2004., and Serge Abiteboul, Angela Bonifati, Gregory Cobena, Ioana Manolescu, and Tova Milo, “Dynamic xml documents with distribution and replication,” in Proc. of SIGMOD Conference 2003, pp. 527-538, 2003., disclose methods for performing distributed arrangement and generation of data in a case where documents are dynamically generated through the Internet. Ugur Cetinternel, Peter J. Keleher, and Yanif Ahmad, “Exploiting precision vs. efficiency tradeoffs in symmetric replication environments,” in Proc. of PODC 2002, p. 128, 2002., discloses a method for selecting, in the case of partly duplicating distributed data, whether to make an update to be reflected or not to ensure predetermined accuracy.
The update process methods disclosed in Yair Amir and Ciprian Tutu, “From total order to database replication,” in Proc. of ICDCS 2002, pp. 494-, 2002., Haifeng Yu and Amin Vahdat, “Minimal replication cost for availability,” in Proc. of PODC 2002, pp. 98-107, 2002., Chi Zhang and Zheng Zhang, “Trading replication consistency for performance and availability: an adaptive approach,” in Proc. of ICDCS 2003, pp. 687-695, 2003., Khuzaima Daudjee and Kenneth Salem, “Lazy database replication with ordering guarantees,” in Proc. of ICDE 2004, pp. 424-435, 2004., Xueyan Tang and Samuel T. Chanson, “Minimal cost replication of dynamic web contents under flat update delivery,” in IEEE Trans. Parallel Distrib. Syst. 15(5): 431-439, 2004., Serge Abiteboul, Angela Bonifati, Gregory Cobena, Ioana Manolescu, and Tova Milo, “Dynamic xml documents with distribution and replication,” in Proc. of SIGMOD Conference 2003, pp. 527-538, 2003., and Ugur Cetinternel, Peter J. Keleher, and Yanif Ahmad, “Exploiting precision vs. efficiency tradeoffs in symmetric replication environments,” in Proc. of PODC 2002, p. 128, 2002., have a problem that a large amount of data needs to be sent in order and to transmit an update operation or an update result. In Yasushi Saito and Marc Shapiro, “Optimistic replication,” in HP Technical report MSR-TR-2003-60, 2003., and Brent ByungHoon Kang, Robert Wilensky, and John Kubiatowicz, “Hash history approach for reconciling mutual inconsistency in optimistic replication,” in Proc. of ICDCS '03, 2003., and Japanese Published Patent Application No. Hei 11 (1999)-306069, and Japanese Patent Translation Publication No. 2003-524243, update detection is performed cluster by cluster after clustering data elements on a database. Consequently, they also have a problem that an amount of communications between a database and a data processing system to check the update becomes large.